Fluid pump or motor with fluid pressure balancing means



Sept.,22, 1959 P. HARTMANN ETAL 2,905,095

FLUID PUMP OR MOTOR WITH FLUID PRESSURE BALANCING MEANS I Filed sept. 1e, 1957 4 sheets-sheet 1 PHILIP HARTMANN G 0 E BRAND AHORA/y Sept. 22, 1959 P. HARTMANN EVAL 2,905,095

FLUID PU ATTORNEY Sept. 22, 1959 P. HARTMANN ET AL 2,905,095

4 Sheets-Sheet 4 /M/EA/TO/Qs- PHILIP HARTMANN GEORGE W. BRAND BKM Q/MW/ v A TTOR/VEV Y United States Patent FLUIDPUMP ORMOTR WITH FLUID PRESSURE BALz-KIJCING` MEANS Philip Hartmann and George W. Brand, Racine, Wis.,

assignors to Hartmann Manufacturing Company, Racine, Wis., a corporationof- Wisconsin Application September 16, 1957, Serial No. 684,305

Claims. (Cl.` 103-125) This invention relates to a iiuid pump or motor, and, more specifically, it relates to a reversiblepump or motor of high fluid pressure application.

Considerable inventing has been done in the field of pumpsand motors; yet, witlithe increased demand for higher efficiencies, lower costs, more power, etc., no pump or motor is known to be designed for performance com` parable to the one described herein. It has long been known that pumps and motors must'overcome'the resisting pressures of the fluid mediums knot just in the direction of movement of the mediums but also in other directions, since the'iiuid mediumwill exert forces in all directions.

This fact causes the fluids to exert an axial force-on the pui-nlp or motor rotor, and, consequently, the axial force must be overcome, and it causes the rotor to bear against the housing with lossin efficiency and excessive wear. Also, in the type of pump or motor employing rollers for sealing the working chamber, the uid pressure exerts a transverse force which tends to bind `the roller and thereby cause a loss in eliiciency. l

It is an object of this invention to provide a fiuid pump or-motor with an improved'porting system for conducting the fluid through the/pump-` or motor. This object particularly results inbalanced axial thrusts on the rotor.

Another object of this inventionis to` provideaA fluid pump `ormotor. with a high efficiency and forhigh'torque at a slow speed if desired. The accomplishmentl of this object results-in a pump or motorr which canbe operated under h-ghfiuid-pressures but atea slow*- speedland a constant motonwithout-jerking.` There isa demand for a motor` with these qualifications for use indriving conveyors, power tools, and other mechanisms.`

Still another object of this inventionV is to provide a fluidlpumpor motor which can bechanged` inA capacity bymerely changing a-part orftwo.

A further object is toprovide a1 rollerV type of fluid pump orf motorl whereinthe rollers are fluid* balancedv so thatl fluidi pressure cannot cause` the rollerstobind:

A generalobject of thisinventionis to improve uid pumps and motors as presently known; p

Otherobjects andl advantages will' become apparent upon reading the following description in conjunction with the accompanying drawings, wherein:

Fig. l is `arsectionalview'of-a preferredembodiment of affiuidlpump` or motor of'this invention, with the section taken on the line 1--1I offFig. 3.

F ig.` Zis a-sectionalfview taken on theline 22fof Fig. l but with the roton shown rotated forty-five degrees and the rollers correspondingly rotated. V

Fig. 3 is a sectionalview takenon'the line 3-3lof Fig. 4 is an enlarged. sectional View of. a1 roller and adjacentk parts of the pump or motor, taken on the line 42--41of Fig. 3.

Fig. 5` is a sectional view takenzron` the line S--S of Fig;.4;

Fig.` 6 is,;a` reduced sectional View taken on the line 6 6 of Fig;.4,

Fig; 7 is a diagrammatic view of the pump or motor housing.

Fig. 8 is an enlarged sectional View of a fragment of that'shown in Fig. 3;

Fig.v 9 is an enlarged sectional view of a' fragment of that shown in Fig, 2, but with parts in a different position.

The same reference numerals refer to the same parts throughout the several views.

The drawings show a fluid pump or motor consisting of a housing including sections 10and. 11, and endcover plates 12 and 13. A rotor 14 is rotatably disposed between the sections 10 and 11, andshaft portions 16 and 17 are shown integral withthef rotor and projectingto axially opposite sides thereof. A conventional two-row ball bearing 18 rotatably supports the shaft portion 17 in thehousing cover plate 13, and a cap 19 and a seal 21 also surround the shaft. An O-ring 22 huid tightly seals the plate 13 with the housing section 11. At this point it should be noticed that the shaft portions and the housing sections have long bearing surfaces at 23 and 24,- and this is provided for high fluid pressure operation along with other similar features mentioned later. Two other O rings 26 and 27 are respectively disposed between the housing sections 10 and 11, and the housing section 10 and the cover plate 12. Here also, a wide annular sealing surface 28 is provided between the housing sections to minimize the possibility of liuidleaks when under high fluidpressure. Of course, the various parts of the pump or motor are bolted together in theusual manner, such as that shown.

The housing section 11 has a circular working chamber 29Y formed in one face thereof and the chamber snugly receives the rotor 14. As used in the claims herein, the temi working chamber means the annulus swept by the hereinafter described vanes of the rotor. Also, four rollers or gates 31 are rotatably mounted in the housing sections 10 and 11 to extend across the plane of the rotor 14, as shown. The rollers are allprovided with cut-outs or` openings 32 in` one side thereof. and intermediate therealong. OfA course, the openings are of a length to have the two diametrically opposite vanes 33 of the rotor 14snugly pass through the openings upon rotation of'both the rotor and the rollers. To assure'per fect timing between the rotor and the roller rotation, herringbone gears 34 and 36 are keyed to the end of the rotor shaft 16 and to the ends of each roller 31, respectively. To keep the rollers in axially xed positions, end plates 37 and 38are secured thereto as shown. Of course7 the hern'ngbonegears maintain the rotating parts in their axial positions.

t Here also it should be noticed that substantial lengths of bearing surfaces 39'and 40 are respectively provided on opposite ends of the rollers and this insures a liuid tight structure at these points. Further, the rollers are of a large uniform diameterfor their extents through the housing sections 10 and 11`, and this feature permits the rollers tobe utilized as alignment pins between the two housing sections. This feature of alignment is important forhigh pressure operation. Also, the capacity of the pump or motor can be very. easily altered by exchanging the rollersfshown for rollers having different size open ings` 32 and by exchangingthe rotor Shown for a rotor having vanes 33 of a size corresponding to the new openings32. Since bothf the rotor and the` rollers have substantial lengths to both sides of the center planes thereof, they are both sturdy and well-balanced.

An important feature. ofthe pump or motor is the arrangement of the fluid passageways `through the housing; Of the: two tiuid passageways 41 and 42 shown inthe respective housingv sections and 11, either one can be employed as the inlet while the other one is the outlet. When the inlet 41 is employed in the motor, fluid enters the housing tol the annular chamber 43 formed in both the housing section 10 and the shaft 16. From there the fluid can enter the two passages 44 and 46Hand flow to the openings 47 and 48 and into the working chamber 29. Figs. 2 and 3, particularly, show the openings 47 and 48 located in the rotor at diametrically opposite positions which locate the openings on the rotationally trailing sides ofthe rotor vanes 33. Thus, the rotor is forced to rotate clockwise as the rollersl 31 also rotate as indicated.

The rotor is symmetrical about a transverse center plane and thus openings 49 and 51 are provided on the opposite side of the vanes, and passages 52. and 53 communicate between the openings and the annular chamber 54. The fluid thus has an outlet through the passages 52 and'53 and the passageway 42. In all instances, the passages and their corresponding openings are considered to each form one passage extended completely through the rotor.

It should be remembered that this pump or motor is intended to withstand high fluid pressures and yet operate at slow speeds without slip. For this reason, the substantial sealing surfaces mentioned are provided and the structure is as described. Since high pressures are intended, it is important to eliminate axial force on the rotor to avoid inefficiency, heat, wear, jerky rotation, and other undesirable results. With the two pairs of passages 44 and 46, and 52 and 53, the lluid pressure is balanced inboth axial directions on the entire rotor. Thus, the rotor has no tendency to bear against the sides of the housing sections or against the walls of the openings .in the rollers. Note that the axially projected area of the left side of the opening 47 and the left side indicated 56 of the passage 44 is equal to the axially projected area of the right side of the opening 47 and the right side indicated 57 of the passage 44. All other passages and openings and chambers in the rotor are similarly axially balanced and, therefore, there is no axial forcefon the rotor.

Another feature of this construction is the balancing of iluid pressure on the rollers 31. In this regard, Fig. 8 shows two portions of a roller 31, namely portions disposed within the angles designated c and (1, exposed to fluid pressure in the working chamber. Of course, this pressure multiplied by the projected or transverse area of the roller portion c and d, and the length of the portions c and d along the roller for the width of the Working chamber as shown in Fig. 4, produces the total forces C and D acting on the roller at these areas c and d which` are equal and are the total portions of the roller exposed to the pressure in the working chamber when the parts are in the Fig. 8 position. The forces C and D cause the roller to bind in position so that the roller cannot freely rotate and a loss in efficiency and smoothness of action is the result. j

In the disclosed structure, forces C and D are balanced in the hereinafter described manner. Fig. 8 also shows two angular portions a and b on the roller 31. Portions a and b are respectively equal to the portions c and d and are diametrically opposite thereto, as shown. Fig. 4 shows openings or chambersSS and 59 in the housing at two planes offset from the working chamber, and the combined lengths of the two Vchambers S8 and S9 are equal to the width of the working chamber. Also, the chambers 58 and 59 are fullyf exposed to the roller 31 and extend to the limits of the angle b, as shown in Figure 8. Thus, fluid pressure in the chambers 58 and 59 will balance the force D acting on the roller.

To provide the necessary uid pressure in the chambers 58 and 59, pressure-balancing passages 61, 62, and 63 are formed in the housing to communicate theworking chamber with the chamber 59. Also, pressure-bal- 4 ancing passages 64, 65, and 66 are formed in the housing to communicate the working chamber with the chamber 58. Fig. 7 is a diagrammatic developed View of the housing, and it shows the passages and the chamber 58. Fig. 6 also shows the porting with regard to the chamber 58. It should now be understood that while Fig. 4 shows passages 61 and 64, these passages would not normally appear in a sectional view of this type since the passages lie within the housing 11 forward of the section line 4-4. However, they are included in Fig. 4 to more clearly show the construction.

Similarly, the drawings show chambers or openings 67 and 68 disposed diametrically opposite to the portion c and subtending the angle a, as shown in Fig. 8. Again, the total exposed area of `chambers 67 and 68 is equal to the area of portion c on the roller. Thus, with lluid pressure in the chambers 67 and 68 equa-lito the fluid pressure in the working chamber, the force C will be balanced by the two forces in the chambers 67 and 68 acting on the roller. Also, pressure-balancing passages 69, 70, and 71 communicate the working chamber with the chamber 67, while passages 72, 73, and 74 communicate the working chamber with the chamber 68.y It should be understood that the chamber 68 is in the plane of the chamber 59. With the four chambers 58, 59, 67, and 68, the machine can be run as a pump or motor in either direction of rotation, and the forces C and d will be balanced to allow the rollers 31 to rotate freely.

Fig. 9 shows the cut-out 32 on the roller, and here also, iluid pressure from the working chamber can cause an unbalance on the roller 31 in the direction shown by the force arrow E This force is balanced by an equal and opposite force F which is created in the pockets or openings 76 and 77 in the roller 31. Here also, the pockets 76 and 77 combined present a total projected area equal to the projected area of the cut-out 32; thus, equal uid pressure in the pockets and the cut-outs will balance the forces, E and R In this instance, a fluid pressure balancing passage 78 and a uid pressure-balancing passage 79 communicate the working chamber with the cut-outs 76 and 77. To show that the projected areas are equal, angles e and f are shown in Fig. 9.

While a specic embodiment of this invention has been shown and described, it should be obvious that certain changes could be made therein and the scope of this invention should, therefore, be limited only by the appended claims.

What is claimed is:

1. A fluid pump or motor comprising a housing having a working chamber, a rotor rotatably mounted in said housing working chamber and including two diametrically opposite vanes, said rotor having a first pair of fluid passages extending therethrough from said working chamber and open at diametrically opposite sides of said rotor adjacent said vanes on one rotational side thereof and to a first transverse plane axially spaced from said working chamber to one side thereof, said housing having a rst fluid passageway in communication with said first pair of passages at said rst transverse plane, said rotor having a second pair of separate fluid passages extending therethrough from said working chamber and open at diametrically opposite sides of said rotor adjacent said vanes and on the other rotational side thereof` and to a.' second transverse plane axially spaced from said working chamber to the other side thereof, said housing having a second lluid passageway in communication with said second pair of huid passages lat said second transverse plane, each said pair of passages being formed to present equal areas on the walls of and for the entire lengths of said passages and axially with respectto said rotor for effecting axially balanced fluid pressures in said passages, a plurality of rollers rotatable in saidhousing and spaced around and projecting across said chamber and having cut-outs therein for the passage of said @senese t vanes upon rotation of said rotor and said rollers, `said .housing having 'fluid openings extending from said chain- `ber to `the diametncally opposite sides of said rollers for balancing lluid pressure on said rollers.

2. A high pressure type of iluid pump or motor of the typeincluding a housing and a shaft supporting a ro-tor with 'two diametrically opposite vanes and rollers having vane cut-outs and disposed to rotate in synchroniza- `tion with the rotation or said vanes which pass through said wane cut-outs, the systern or porting said pump or motor `by said housing having two separate uid passage- "Ways--therein spaced apart and in iluid communication with the interior of `said housing on axially opposite sides `of said rotor, said rotor having a pair ot fluid passages in Liluid communication with each said passageway and extending through said rotor to separate rotational sides of said vanes, the projected areas of said passages, when "projectedlaxially olf said rotor, being equal on the axially opposite sides of said passages to thereby have axially 'balanced `iluid`forces acting in said passages, said housng`having fluid-openings extending from the interior of said housing to ends at the diametrically opposite sides of said rollers, `said housing having recesses therein for communicating with said ends of said openings Ito balance fluid pressure acting on said rollers at the interior of said housing.

V3. A fluid pump or motor for high pressure fluid, comprising a housing, a rotor rotatably mounted in said housing `and including a vane projecting radially therefrom, a plurality of rollers rotatably mounted in said Yhousing with the axes thereof spaced from the axis of -said rotor and each of said rollers having a cutout there- `in"for`the movement of said vane therethrough upon synchronized rotation of said rotor and said rollers, the lengths of said rollers extending across and axially beyond the planes of the side faces of said rotor for a distance at least the width of said vane and with said rollers being of a uniform diameter throughout said lengths, said housing being formed in two sections each respectively receiving opposite ends of said lengths of said rollers with the latter thereby serving as alignment members when said two sections are joined together, said housing having fluid openings extending from the interior of said housing to the diametrically opposite sides of said rollers at opposite ends of said lengths, said housing having recesses therein at said opposite ends for communicating with said openings to balance Huid pressure acting on said rollers at the interior of said housing.

4. A high pressure fluid pump or motor of the type including a housing and a shaft supporting a rotor with a radially projecting vane and roller gates with cut-outs for movement therethrough of said vane, the system of porting said pump or motor by providing said housing with two fluid passageways extended therein and spaced with one to each side of the plane of rotation of said vane, said housing having an annular duid chamber in communication with the interior end of each said passageway and concentric with said rotor, and said rotor having Huid passages obliquely disposed therethrough and respectively communicating with each .said chamber and rotationally opposite sides of said vane, said housing and said rollers having fluid openings extend-ing from the interior of said housing and also through said rollers to the diametrically opposite sides of said rollers, said housing and said rollers having recesses therein located at and communicating with the terminal ends of said openings to balance uid pressure acting on said rollers at the interior of said housing.

5. A iluid pump or motor for high pressure duid, comprising a housing including two circular side walls in spaced-apart planes, a ro-tor rotatably mounted in said housing intermediate said side walls rand including a vane projecting radially therefrom, a plurality of rollers rotatably mounted in said housing with the axes thereof spaced from the axis of said rotor and each of said rollers havis ing ra cut-out therein for the movement .of ^said wane therethrough upon synchronized rotation `-of said rotor vand ysaid rollers, 'said rollers lextending and being of `a uniform diameter for the entire length thereof across and-axially beyond saidrplanes of said wallsof said housing fora distance at least the width of said vane,rsaid walls of said vhousing and `said roller having fluid openings extending therethrough to the diametrically opposite .sides of said rollers and axially outside .of :said planes of said walls, said housing and said rollers having .recesses therein for communicating with said openings toibalance `fluid pressure acting on said rollers at the interior of said housing.

6. A high pressure fluid pump or `motor of the `type including .a housing and a .shaft supporting a rotor with a radially projecting vane androller .gates with cut-outs `for movement therethrough of said vane, the .system of porting saidpuinp or motor by providing said housing -with ailuid passageway extendedtherein and `spaced to `each side of the two planes of the two sides orf-said vane,

said rhousing having an annular fluid ,chamber `in com- :munication withthe interior end -of each said passageway and concentric.withsaidrotor,` and said rotor havinglluid passages obliquely disposedtherethrough and respectively communicating with each said-chambenand rotationally opposite sides of `said vane,.said housing having recesses exposed to said `roller .gates `at locations axially offset fromsaid planes of said vanes -with saidrecesses being diametrically opposite to and of a total projected area toward-said ro'llergates equal to the `total .projected area ofsaid roller gates exposed -to said-chamber at any one instant when said roller gates are in a udsealng posi- .tionlwith -said rotor, Yand .said `housing ihaving Aopenings extending .from said chamber to said recesses for balancing iluid pressure on said roller gates.

7. A high pressure iluid pump or motor of the type including a housing and a shaft supporting a rotor with a radially projecting vane and roller gates with cut-outs for movement therethrough of said vane, the system of porting said pump or motor by providing said housing with a fluid passageway extended therein and spaced to each side of the planes of rotation of the sides of said vane, said housing having an annular fluid chamber in communication with the interior end of each said passageway and concentric with said rotor, and said rotor having fluid passages obliquely disposed therethrough and respectively communicating with each said chamber and rotationally opposite sides of said vane, said housing having recesses exposed to said roller gates at locations offset axially outside of said planes of said vanes with said recesses being diametrically opposite to and of a total projected area toward said roller gates equal to the total projected area of said roller gates exposed to said chamber iat any one instant when said gates are fluid sealing with said rotor, and said housing having openings extending from said chamber to said recesses for partly balancing iluid pressure on ysaid roller gates, and said roller gates having pockets therein at locations in the plane of said recesses of said housing andwith said pockets being diametrically opposite to and of a total projected area toward said roller gates equal to the total projected area of said cut-outs of said roller gates, and said roller gates having Huid-balancing passages extending from said cutouts to said pockets for further balancing fluid pressure on said roller gates.

8. In a iluid pump or motor of the type employing a housing supporting a fixed-vane rotor androllers synchronized with the rotation of the rotor vanes and disposed across the working chamber in the housing, the invention characterized by said housing having fluid pressure-balancing passages on each side of said rollers and spaced apart a distance less than the widths of said vanes and extending from saidworking chamber in the area swept by rotation of said vanes to locations diametrically opposite on said rollers and in planes offset from said working' chamber, said pump or motor having Huid openings at said locations for receiving fluid from said passages, the areas of said openings projected toward said rollers being equal to the projected areas of said rollers exposed to luid pressure in said working chamber when said roller is fluid sealing with said rotor for balancing radial forces acting on said rollers in said working chamber.

9. In a uid pump or motor of the type employing a housing supporting a fixed-vane rotor and rollers synchronized with the rotation of the rotor and having cutouts for the passage of the vanes and disposed across the working chamber in the housing, the invention characterized by said housing having uid pressure-balancing passages extending from said working chamber to iirst loca tions diametrically opposite on said rollers and in planes olset from said working chamber, said housing having uid openings at said locations for receiving ii-uid from said passages, the projected areas of said openings toward l said rollers being equal to the projected areas of said rollers exposed to liuid pressure in said working chamber for balancing radial forces acting on said rollers in said working chamber when said rollers are fluid sealing with said rotor, said rollers having fluid pressure-balancing passages extending therethrough from said cut-outs to diametrically opposite sides to second locations at the planes of said fluid openings, said rollers having pockets at said second locations for receiving uid from said passages in said rollers, the projected areas of said pockets toward said rollers being equal to the projected areas of said cutouts for balancing radial forces acting on said rollers at said cut-outs.

10. In a fluid pump or motor of the type including a housing supporting a vane-type rotor and rollers rota- 4tionally synchronized with said rotor and having cut-outs for the passage of the vanes and said rollers being disposed across the working chamber in said housing, the invention characterized by said housing having ,two iluid 4to balance the radial forces acting on said roller at said working chamber, said roller thavingrtwo fluid pressureregulating passages extending therethrough from said cutout to diametrically opposite sides to two second locations with one in each of the two said planes, said roller having two pockets at said two second locations for receiving Huid pressure from said passages in said roller to balance the radial forces acting on said roller at said cut-out.

References Cited in the tile of this patent UNITED STATES PATENTS 622,949 Green Apr. '11, 1899 1,268,248 Jackman et al June 4, 1918 1,395,114 Jackman Oct.25, 1921 1,729,826 Green Oct. 1, 1929 2,111,883 Burghauser Mar. 22, 1938 2,319,374 Ungar May 18, 1943 2,735,371 Johnson Feb. 21, 1956 

